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Lab I final presentation
- 1. FRICTIONAL HEAD LOSSES IN PIPES TALKING HEADS CLAUDE COLLIER KELSEY HENDERSON GARRET OZBOLT MICHAEL SCOTT-PIESCO 1
- 2. PRESSURE DROP IN PIPES: INTRODUCTION • Necessity of Fluid Transport • Fluids move from high to low energy state • Incur energy losses • Pump Sizing • Piping Arrangement 2
- 3. PRESSURE DROP IN PIPES: INTRODUCTION • Energy Equation for Fluids: 𝑃1 𝛾 + 𝛼1 𝒗1 2 2𝑔 + 𝑧1 + ℎ 𝑝 = 𝑃2 𝛾 + 𝛼2 𝒗2 2 2𝑔 + 𝑧2 + ℎ 𝑇 + ℎ𝑙 ℎ𝑙 = ℎ 𝑓 + ℎ 𝑐 3
- 4. FRICTION IN PIPES • “Skin Friction” ∆𝑃 𝛾 = ℎ 𝑓 or …. ∆𝑃 = 𝛾ℎ 𝑓 4 𝑃1 𝛾 + 𝛼1 𝒗1 2 2𝑔 + 𝑧1 + ℎ 𝑝 = 𝑃2 𝛾 + 𝛼2 𝒗2 2 2𝑔 + 𝑧2 + ℎ 𝑇 + ℎ 𝑓 + ℎ 𝑐
- 5. FANNING FRICTION FACTOR 5 • Definition: “The drag force per wetted surface unit area (shear stress at the surface) divided by the product of density times the velocity head.” 𝑓 = ∆𝑃 𝐿 𝑅 𝜌𝑣2 Head Loss: Operative: ℎ 𝑓 = 4𝑓 𝐿 𝐷 𝑣2 2𝑔 ∆𝑃 = 4𝑓 𝐿 𝐷 𝜌𝑣2 2
- 6. FLOW REGIMES 6 • Reynold’s Number
- 9. ORIFICE METERS 9 • Plate with bore • Pressure taps on both sides • Measures Flow • 𝑄 = 𝐶 𝑂 𝐴 𝐵 2∆𝑃 𝜌(1−𝛽4)
- 10. OBJECTIVES • Qualitatively determine relationship between friction losses, Reynolds number, and relative roughness • Estimate orifice meter coefficient • Estimate absolute roughness of PVC pipe 10
- 11. SAFETY 11
- 12. EQUIPMENT 12
- 13. ROTAMETERS 13 • Height of float is directly proportional to fluid flow rate. This one measures in percent flow.
- 14. PROCEDURE • Produce rotameter calibration curve • Direct flow using valves on assembly • Connect DP cell to pressure taps on desired pipe or component • Set flow to 100% flow on rotameter, and begin decreasing until 0%, recording DP meter output along the way • Run procedure for 1" pipe, 3/4" pipe, and orifice meter 14
- 15. CALCULATING FANNING FRICTION FACTOR AND REYNOLDS NUMBER 15
- 16. COMPARISON OF REYNOLDS NUMBER AND FANNING FRICTION FACTOR 16 0 0.002 0.004 0.006 0.008 0.01 0.012 0 10000 20000 30000 40000 50000 60000 70000 80000 Fanningfrictionfactor Reynolds number 1" Schedule 80 PVC pipe 3/4" Schedule 80 PVC pipe
- 17. COMPARISON OF REYNOLDS NUMBER AND FANNING FRICTION FACTOR OF DIFFERENT PRESSURE TAPS 17 0 0.002 0.004 0.006 0.008 0.01 0.012 0 10000 20000 30000 40000 50000 60000 70000 Fanningfrictionfactor Reynolds number Taps 1&5 Taps 1&4 Taps 2&4 Taps 2&5
- 18. CALCULATE ABSOLUTE ROUGHNESS COEFFICIENT: SHACHAM EQUATION 18 ε = 0.0082 Accepted value: 0.0015
- 19. FINDING ORIFICE METER COEFFICIENT: PLOT VOLUMETRIC FLOWRATE AGAINST SQUARE ROOT OF PRESSURE 19 y = 1.2072x - 26.347 R² = 0.99973 0 100 200 300 400 500 600 700 800 900 0 100 200 300 400 500 600 700 VolumetricFlowRate(cm3/s) P1/2 (cm1/2 H2O)
- 20. FINDING ORIFICE METER COEFFICIENT: USE SLOPE OF GRAPH TO SOLVE FOR COEFFICIENT 20 Co = 0.754 Accepted value: 0.6-0.65
- 21. IN CONCLUSION Fanning friction factor and Reynolds Number Showed the expected trends quantitatively Error at lower flow rates due to differential pressure readings 9/23/15 Convective Heat Transfer Experiment 21 0 0.001 0.002 0.003 0.004 0.005 0.006 0.007 25000 30000 35000 40000 45000 50000 55000 60000 Fanningfrictionfactor Reynolds number Taps 1&5 Taps 1&4 Taps 2&4 Taps 2&5
- 22. IN CONCLUSION Relative roughness of pipe Produced result 10X larger than expected, 0.014mm as opposed to accepted value of 0.0015mm, error most likely from differential pressure meter readings being off 22
- 23. IN CONCLUSION Orifice meter coefficient Value of 0.75 is slightly high, however reasonable given the accepted value is 0.6-0.65 23
- 25. QUESTIONS? Thank you for your attention 25